Name: creation and transplantation of an adipose-derived stem cell (asc) sheet in a diabetic wound-healing model
Uploaded: 2017-08-04T12:30:00
Description: Watch this Scientific Journal Video about Creation and Transplantation of an Adipose-derived Stem Cell ASC Sheet in a Diabetic Wound-healing Model at JoVE.com

The authors thank Dr. Yukiko Koga of the Department of Plastic and Reconstructive Surgery, Juntendo University School of Medicine, for providing practical advice. We also thank Mr. Hidekazu Murata of the Diabetic Center of Tokyo Women&#8217;s Medical University School of Medicine for excellent technical support. This study was supported by the Creation of Innovation Centers for Advanced Interdisciplinary Research Areas Program of the Project for Developing Innovation Systems &#8220;Cell Sheet Tissue Engineering Center (CSTEC)&#8221; from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan.

All experimental protocols presented below were approved by the Animal Welfare Committee of Tokyo Women&#39;s Medical University School of Medicine and abided by all requirements of the Guidelines for Proper Conduct of Animal Experiments.
1. Preparation of Animals, Instruments, Culture Media, and Dishes
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	<li>Prepare complete culture medium using minimum essential medium alpha containing 20% fetal bovine serum (FBS) and 1% penicillin/streptomycin. Store this for several months at 4 &#176...

<ol>
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C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multipotential+human+adipose-derived+stromal+stem+cells+exhibit+a+perivascular+phenotype+in+vitro+and+in+vivo.">Multipotential human adipose-derived stromal stem cells exhibit a perivascular phenotype in vitro and in vivo.</a> J Cell Physiol. 214 (2), 413-421 (2008).</li><li>Kern, S., Eichler, H., Stoeve, J., Kluter, H., Bieback, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+of+mesenchymal+stem+cells+from+bone+marrow,+umbilical+cord+blood,+or+adipose+tissue.">Comparative analysis of mesenchymal stem cells from bone marrow, umbilical cord blood, or adipose tissue.</a> Stem Cells. 24 (5), 1294-1301 (2006).</li><li>Casteilla, L., Planat-Benard, V., Laharrague, P., Cousin, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adipose-derived+stromal+cells:+Their+identity+and+uses+in+clinical+trials,+an+update.">Adipose-derived stromal cells: Their identity and uses in clinical trials, an update.</a> World J Stem Cells. 3 (4), 25-33 (2011).</li><li>Zuk, P. 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The most critical steps for successfully culturing an rASC sheet are as follows: 1) The temperature must be maintained at approximately 37 &#176;C during culturing on the temperature-responsive culture dishes. During the creation of an rASC sheet, every procedure was performed on a 37 &#176;C thermo-plate, and every reagent was warmed to 37 &#176;C to prevent the cells from spontaneously detaching from the dish31. 2) The recipient ZDF rats must be monitored to prevent the removal of the non-adhesi...

The population of diabetic patients is increasing worldwide and reached 400 million in 20151; an estimated 15 - 25% of patients with diabetes are at risk from the progression of a lower-extremity diabetic ulcer2. Lower-extremity diabetic ulcers are intractable and might require a prolonged therapeutic period with rehabilitation training after complete recovery. A long therapy period often results in a significant reduction in patient quality of life. Thus, new therapies that decrease or prevent aggravation must be developed for the treatment of diabetic wounds. To evaluate diabetic wound healing, we optimized a diabetic ulcer wound-healing model in rats, which mimics practical clinical conditions, and evaluated whether transplanting adipose-derived stem cell (ASC) sheets using cell-sheet engineering accelerated wound healing.
Mesenchymal stromal cells (MSCs) exhibit an excellent potential for accelerating wound healing because of their self-renewal capacity, their immunomodulatory effects, and their ability to differentiate into various cell lineages3. ASCs are a type of MSC derived from adipose tissue, and they exhibit several advantages over MSCs derived from other tissues, including their angiogenic potential and paracrine activity4,5. Adipose tissue is relatively abundant in the human body, and its accessibility allows for collection using minimally invasive procedures. Therefore, ASCs have been used experimentally for wound-healing applications6,7.
Previous reports have shown that the direct injection of single-cell MSC suspensions into areas around wounds can accelerate wound healing8,9. However, despite reports of the acceleration of wound healing in diabetic ulcer models following the injection of single-cell suspensions, the survival time of transplanted cells at the wound site is not clear.
In this study, we applied cell-sheet engineering using temperature-responsive culture dishes. These dishes have the temperature-responsive polymer N-isopropylacrylamide covalently bound onto their surface10. The grafted polymer layer allows for temperature-controlled cell adhesion to or detachment from the surface of the culture dish. The surface of the dish becomes hydrophobic at 37 &#176;C, allowing cells to adhere and proliferate, whereas cells spontaneously detach from the surface when it becomes hydrophilic at temperatures below 32 &#176;C. Cultured cells can be harvested as a contiguous cell sheet with intact cell-to-cell junctions and extracellular matrices (ECMs) simply by reducing the temperature; thus, proteolytic enzymes that damage the ECM, such as trypsin, are not required11. Therefore, cell-sheet engineering can preserve cell-to-cell connections and improve the efficacy of cell transplantation.
In addition, cell-sheet transplantation increases cell survival rates when compared to cell injection12.In this protocol, Zucker diabetic fatty (ZDF) rats were selected as a type 2 diabetes and obesity model with delayed wound healing. ZDF rats spontaneously develop obesity at approximately 4 weeks. They then develop type 2 diabetes with obesity between 8 and 12 weeks of age, at which point they exhibit hyperglycemia associated with insulin resistance, dyslipidemia, and hypertriglyceridemia13. Delayed wound healing, reduced blood flow in peripheral blood vessels, and diabetic nephropathy are also observed14,15,16. Moreover, ZDF rats might be an appropriate model for studying the healing of intractable cutaneous ulcers, such as diabetic ulcers.
The differences between humans and rodents in wound-healing mechanisms are associated with anatomical differences in the skin. Wound healing in normal rats is based on wound contraction, whereas wound healing in humans is based on re-epithelialization and granulation tissue formation. Typically, wound splinting used in rodent models helps to minimize wound contraction and allows for the gradual formation of granulation tissue17, although wounds in nondiabetic rats are almost completely closed by contraction. However, diabetic wound contraction in ZDF rats is impaired, and wound healing primarily occurs through re-epithelialization and granulation tissue formation; thus, this process is more similar to human wound healing14.
Diabetic wounds with exposed bone after debridement are often encountered clinically. Previous studies have examined 12-mm diameter full-thickness skin wounds on the backs of athymic nude mice18,19 and 10-mm diameter full-thickness skin wounds on the backs of normal mice20. To develop a clinical model for severe diabetic wounds, larger (15 x 10 mm2) full-thickness skin defects with exposed bone and without the periosteum were created, as previously described21, in rats with type 2 diabetes and obesity.
Rat ASC (rASC) sheets from the ASCs of normal Lewis rats were created through the allogenic transplantation of ASC sheets. In clinical practice, autologous transplantation is unfeasible because diabetic patients with ulcers often exhibit severe diabetic complications, such as uncontrolled high blood glucose levels and high body mass indices, and these complications cause wound-healing disorders that increase the difficulty of obtaining adipose tissue from these patients. Furthermore, ASCs from animals with diabetes exhibit altered properties and impaired function22. Therefore, the protocol presented here describes the allogenic transplantation of rASC sheets from normal rats and the application of artificial skin to diabetic rats.
The bilayer artificial skin used in this protocol prevents the spontaneous contraction of the wounds, promotes the synthesis of a new connective tissue matrix, and resembles the true dermis23. In this protocol, artificial skin is placed on an rASC sheet and fixed with nylon threads to prevent wound contraction or enlargement resulting from loose rat skin. In addition, the artificial skin provides a three-dimensional framework for the ASC sheets, maintains a moist environment for the transplanted ASC sheets and wounds, and protects the wounds from infection and external forces. Finally, a non-adhesive dressing is placed over the wound to protect it from external impact, maintain a moist wound environment, and absorb exudate.
An rASC sheet is thin, flexible, and deformable and can be adhered to moving recipient sites, such as a beating heart24. Cell-sheet engineering has been used for the reconstruction of various tissues and can generate curative effects25,26. ASC sheets that exhibit clinical therapeutic potential might accelerate the healing of many types of wounds. Moreover, the allogeneic transplantation of ASC sheets, combined with the use of artificial skin, might be applicable to the treatment of intractable ulcers or burns, such as those observed in peripheral arterial disease or collagen disease, or they may be administered to patients who are undernourished or are using steroids. This approach increases the efficiency of transplanting ASCs. The wound-healing ZDF rat model produces a severe wound condition that resembles the human wound healing process and mimics clinical conditions in a small-sized experimental animal.

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			<td height="21" style="height:21px;width:223px;">&#945;-MEM glutamax</td>
			<td style="width:169px;">Invitrogen</td>
			<td style="width:119px;">32571-036</td>
			<td style="width:167px;">Carlsbad, CA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Fetal bovine serum (FBS)</td>
			<td>Japan Bioserum Co Ltd.</td>
			<td style="width:119px;">S1650-500</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Penicillin/streptomycin</td>
			<td>Life Technologies</td>
			<td style="width:119px;">15140-122</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Collagenase A</td>
			<td>Roche Diagnostics</td>
			<td style="width:119px;">10 103 578 001</td>
			<td>Mannheim, Germany</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">60-cm2 Primaria tissue culture dish</td>
			<td>BD Biosciences</td>
			<td>353803</td>
			<td>Franklin Lakes, NJ</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dulbecco&#39;s Phosphate Buffer Saline (PBS)</td>
			<td>Life Technologies</td>
			<td style="width:119px;">1490-144</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">0.25% Trypsin-ethylenediamine tetraacetic acid (EDTA)</td>
			<td>Life Technologies</td>
			<td style="width:119px;">25200-056</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">L-ascorbic acid phosphate magnesium salt n-hydrate</td>
			<td style="width:169px;">Wako</td>
			<td>013-19641</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">35-mm temperature-responsive culture dish (UpcellTM)</td>
			<td>CellSeed</td>
			<td>NUNC-174904</td>
			<td>Tokyo, Japan</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Microwarm plate (MP-1000)</td>
			<td style="width:169px;">Kitazato Science Co., Ltd.</td>
			<td style="width:119px;">1111</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rodent mechanical ventilator</td>
			<td>Stoelting</td>
			<td>#50206</td>
			<td>Wood Dale, IL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">4% isoflurane</td>
			<td>Pfizer Japan</td>
			<td>114-13340-3</td>
			<td>Tokyo, Japan</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">Artificial skin (Pelnac&#174;)</td>
			<td>Smith &#38; Nephew</td>
			<td>PN-R40060</td>
			<td>&#160;Tokyo, Japan</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">Non-adhesive dressing (Hydrosite plus&#174;)</td>
			<td>Smith &#38; Nephew</td>
			<td align="right">66800679</td>
			<td>Known as Allevyn non-adhessing&#174; in the United State</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">5-0 nylon suture</td>
			<td>Alfresa</td>
			<td style="width:119px;">EP1105NB45-KF2</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">20 CELLSTAR TUBES</td>
			<td>greiner bio-one</td>
			<td style="width:119px;">227 261</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">15mL Centrifuge Tube</td>
			<td>Corning Incorporated</td>
			<td align="right" style="width:119px;">430791</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:223px;">14 GOLDMAN-FOX PERIOSTEAL</td>
			<td>Hu-Friedy</td>
			<td style="width:119px;">P14</td>
			<td>Chicago, IL</td>
		</tr>
	</tbody>
</table>

creation and transplantation of an adipose-derived stem cell (asc) sheet in a diabetic wound-healing model

Artificial skin has achieved considerable therapeutic results in clinical practice. However, artificial skin treatments for wounds in diabetic patients with impeded blood flow or with large wounds might be prolonged. Cell-based therapies have appeared as a new technique for the treatment of diabetic ulcers, and cell-sheet engineering has improved the efficacy of cell transplantation. A number of reports have suggested that adipose-derived stem cells (ASCs), a type of mesenchymal stromal cell (MSC), exhibit therapeutic potential due to their relative abundance in adipose tissue and their accessibility for collection when compared to MSCs from other tissues. Therefore, ASCs appear to be a good source of stem cells for therapeutic use. In this study, ASC sheets from the epididymal adipose fat of normal Lewis rats were successfully created using temperature-responsive culture dishes and normal culture medium containing ascorbic acid. The ASC sheets were transplanted into Zucker diabetic fatty (ZDF) rats, a rat model of type 2 diabetes and obesity, that exhibit diminished wound healing. A wound was created on the posterior cranial surface, ASC sheets were transplanted into the wound, and a bilayer artificial skin was used to cover the sheets. ZDF rats that received ASC sheets had better wound healing than ZDF rats without the transplantation of ASC sheets. This approach was limited because ASC sheets are sensitive to dry conditions, requiring the maintenance of a moist wound environment. Therefore, artificial skin was used to cover the ASC sheet to prevent drying. The allogenic transplantation of ASC sheets in combination with artificial skin might also be applicable to other intractable ulcers or burns, such as those observed with peripheral arterial disease and collagen disease, and might be administered to patients who are undernourished or are using steroids. Thus, this treatment might be the first step towards improving the therapeutic options for diabetic wound healing.

This protocol attempted to establish a new cell-based therapy for intractable diabetic wounds. Briefly (as illustrated in Figure 1), allogeneic rASC sheets were created from normal rats using cell-sheet engineering and were then transplanted using a bilayer of artificial skin onto a full-thickness skin defect on a diabetic rat. Light microscope images of a good example of an rASC sheet (Figure 2A) and a bad example of an rASC sheet (Figure 2B</str...

Watch this Scientific Journal Video about Creation and Transplantation of an Adipose-derived Stem Cell ASC Sheet in a Diabetic Wound-healing Model at JoVE.com

Creation and Transplantation of an Adipose-derived Stem Cell ASC Sheet in a Diabetic Wound-healing Model

Adipose-derived stem cells (ASCs) are easily isolated and harvested from the fat of normal rats. ASC sheets can be created using cell-sheet engineering and can be transplanted into Zucker diabetic fatty rats exhibiting full-thickness skin defects with exposed bone and then covered with a bilayer of artificial skin.

Creation and Transplantation of an Adipose-derived Stem Cell (ASC) Sheet in a Diabetic Wound-healing Model

Artificial skin has achieved considerable therapeutic results in clinical practice. However, artificial skin treatments for wounds in diabetic patients ...

The overall goal of this procedure is to verify the effect of adipose-derived stem cell sheets combined with artificial skin on wound healing for a large full-thickness skin defect in diabetic rat. This method can help answer key questions about healing of chronic wound, such as diabetic large wound with exposed bone. The main advantage of this technique is that cells are transplanted to the wound in solid sheets using cell sheet technology, and the result is a viable, stable transplant.For a fat pad donor, plan to use eight to 33 week old Lewis rats. At the surgical site, have ready several sterile cotton-tipped applicators, gauzes, a scalpel, a needle holder, operating scissors, a pair of forceps, and 5-0 nylon suture. For temporary tissue placement, load a 100 milliliter petri dish with 10 milliliters of PBS.Weigh the PBS-loaded dish to later find the mass of the harvested tissue. After anesthetizing the rat, position it supine on a sterile drape. Then, shave the operative area and scrub the exposed skin using several alternating scrubs of 70%ethanol.Now, make a three centimeter skin incision in the lateral lower abdomen. Next, expose and dissect the external oblique muscle. Then, expose the epididymal adipose tissue surrounding the epididymis.Next, carefully excise the epididymal adipose tissue. Avoid damaging the epididymis, testes, and epididymal blood vessels. Transfer the tissue into the dish of PBS.Then, close up the donor rat and follow standard postoperative care practices. Isolate the ASCs from two to three grams of harvested adipose tissue. Digest the tissue for an hour in 0.1%type A collagenase to obtain the stromal vascular fraction, or SVF.After purifying the SVF, suspend the SVF in 20 milliliters of media. Split the suspension into two 60 square centimeter culture dishes, and culture them for 24 hours under standard conditions. The next day, wash the plates with PBS three times to remove any unattached cells and debris.After the final wash, add back fresh complete medium. Then, continue to passage the cells until they are nearly sub confluent on the third day of culturing. Then, using one milliliter of 0.25%trypsin EDTA in a brief incubation.Remove the cells from the plate. Do not let the cells be exposed to active trypsin more than 10 minutes. After observing and counting the cells, subculture them at a density of 1, 700 per square centimeter.Then, pass the cells every three days, and complete three passages before proceeding. After passing the subcultured rat ASCs for the third time, plate 150, 000 cells onto a 35 millimeter diameter temperature-responsive culture dish, and two milliliters of culture medium. Culture the dish for three days in an incubator to make a uniform cell sheet.Three days later, change the medium, and add 16.4 micrograms per milliliter of AA.Then culture the cells, changing the AA medium every other day. After four or five days on the AA-containing medium, check the proliferation of the ASCs. Look for gaps between the cells and the contiguous cell sheet.Once a contiguous cell sheet is established, the cells can be used for the model. When needed, collect the cell sheet by placing the plate at room temperature for 15 to 20 minutes. Because the plate is temperature sensitive, the cells will spontaneously detach as a contiguous sheet, and the sheet can be removed with forceps.For the obesity wound healing model, use adult male ZDF rats, 16 to 18 weeks old weighing between 500 and 600 grams. Position and anesthetize rat on the surgical field, and before shaving the head, clean it using 70%ethanol. Then, shave the operative area and clean the exposed skin with alternating scrubs of 70%ethanol.Around this time, transfer the temperature sensitive plate of adipose stem cells to the bench. Before the cell sheet detaches from the plate, remove the medium and wash the cell sheet with PBS three times. After collecting the cell sheet, soak it in PBS until needed.Once the cells are ready, make a 15 by 10 millimeter full-thickness skin defect on the rat's head. First, remove the cutaneous tissue down to the periosteum. Then, excise the skin an cutaneous tissue with a scalpel and a pair of surgical scissors.To complete the defect, remove the periosteum with the periosteal raspatory. Then place the cell sheet over the defect. The stem cell sheet is soft and flexible.Use forceps to extend it to every corner of the defect. Now, cover the cell sheet and defect with a 10 by 15 millimeter patch of artificial skin soaked in saline right before use, and close the wound with approximately 10 stitches using 5-0 nylon suture. To protect the wound, use 5-0 nylon suture to secure a 15 by 20 millimeter patch of non-adhesive dressing over the artificial skin.Plan to observe the dressing every other day, because the rat will invariably remove it, and if needed, replace the dressing promptly. In two groups of six Zucker diabetic fatty rats, the described protocol was used to create a skull defect. Experimental rats were treated with a rat adipose stem cell sheet, and the controls were not.After 14 days, the wounds of the treatment group were significantly smaller than those of the controls. After watching this video, you should have a good understanding of how to make large wound with exposed bone in rats, and then treat that wound with adipose derived stem cells. While attempting this procedure, be sure to use strict temperature management during the entire process of using temperature responsive culture dishes.Otherwise, cells could spontaneously detach from the dishes, delaying your experiments.

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Research

JoVE Journal

Medicine

Orthotopic Aortic Transplantation: A Rat Model to Study the Development of Chronic Vasculopathy

Research models of chronic rejection are essential to investigate pathobiological and pathophysiological processes during the development of transplant vasculopathy (TVP).
The commonly used animal model for cardiovascular chronic rejection studies is the heterotopic heart transplant model performed in laboratory rodents. This model is used widely in experiments since Ono and Lindsey (3) published their technique. To analyze the findings in the blood vessels, the heart has to be sectioned and all vessels have to be measured.
Another method to investigate chronic rejection in cardiovascular questionings is the aortic transplant model (1, 2). In the orthotopic aortic transplant model, the aorta can easily be histologically evaluated (2). The PVG-to-ACI model is especially useful for CAV studies, since acute vascular rejection is not a major confounding factor and Cyclosporin A (CsA) treatment does not prevent the development of CAV, similar to what we find in the clinical setting (4). A7-day period of CsA is required in this model to prevent acute rejection and to achieve long-term survival with the development of TVP.
This model can also be used to investigate acute cellular rejection and media necrosis in xenogeneic models (5).

This video demonstrates the orthotopic aortic transplant model as a simple model to study the development of transplant vasculopathy (TVP) in rats.

Research models of chronic rejection are essential to investigate pathobiological and pathophysiological processes during the development of transplant ...

A Mouse Model of in Utero Transplantation

The transplantation of stem cells and viruses in utero has tremendous potential for treating congenital disorders in the human fetus. For example, in utero transplantation (IUT) of hematopoietic stem cells has been used to successfully treat patients with severe combined immunodeficiency.1,2 In several other conditions, however, IUT has been attempted without success.3 Given these mixed results, the availability of an efficient non-human model to study the biological sequelae of stem cell transplantation and gene therapy is critical to advance this field. We and others have used the mouse model of IUT to study factors affecting successful engraftment of in utero transplanted hematopoietic stem cells in both wild-type mice4-7 and those with genetic diseases.8,9 The fetal environment also offers considerable advantages for the success of in utero gene therapy. For example, the delivery of adenoviral10, adeno-associated viral10, retroviral11, and lentiviral vectors12,13 into the fetus has resulted in the transduction of multiple organs distant from the site of injection with long-term gene expression. in utero gene therapy may therefore be considered as a possible treatment strategy for single gene disorders such as muscular dystrophy or cystic fibrosis. Another potential advantage of IUT is the ability to induce immune tolerance to a specific antigen. As seen in mice with hemophilia, the introduction of Factor IX early in development results in tolerance to this protein.14 
In addition to its use in investigating potential human therapies, the mouse model of IUT can be a powerful tool to study basic questions in developmental and stem cell biology. For example, one can deliver various small molecules to induce or inhibit specific gene expression at defined gestational stages and manipulate developmental pathways. The impact of these alterations can be assessed at various timepoints after the initial transplantation. Furthermore, one can transplant pluripotent or lineage specific progenitor cells into the fetal environment to study stem cell differentiation in a non-irradiated and unperturbed host environment.
The mouse model of IUT has already provided numerous insights within the fields of immunology, and developmental and stem cell biology. In this video-based protocol, we describe a step-by-step approach to performing IUT in mouse fetuses and outline the critical steps and potential pitfalls of this technique.

A Mouse Model of in Utero Transplantation

The mouse model of in utero transplantation is a versatile tool that can be used to study the potential clinical applications of stem cell transplantation and gene therapy in the fetus. In this protocol, we present a general approach to performing this technique

The transplantation of stem cells and viruses in utero has tremendous potential for treating congenital disorders in the human fetus.  For example, in ...

Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model

Stem cell transplantation protocols are finding their way into clinical practice1,2,3. Getting better results, making the protocols more robust, and finding new sources for implantable cells are the focus of recent research4,5. Investigating the effectiveness of cell therapies is not an easy task and new tools are needed to investigate the mechanisms involved in the treatment process6. We designed an experimental protocol of ischemia/reperfusion in order to allow the observation of cellular connections and even subcellular mechanisms during ischemia/reperfusion injury and after stem cell transplantation and to evaluate the efficacy of cell therapy. H9c2 cardiomyoblast cells were placed onto cell culture plates7,8. Ischemia was simulated with 150 minutes in a glucose free medium with oxygen level below 0.5%. Then, normal media and oxygen levels were reintroduced to simulate reperfusion. After oxygen glucose deprivation, the damaged cells were treated with transplantation of labeled human bone marrow derived mesenchymal stem cells by adding them to the culture. Mesenchymal stem cells are preferred in clinical trials because they are easily accessible with minimal invasive surgery, easily expandable and autologous. After 24 hours of co-cultivation, cells were stained with calcein and ethidium-homodimer to differentiate between live and dead cells. This setup allowed us to investigate the intercellular connections using confocal fluorescent microscopy and to quantify the survival rate of postischemic cells by flow cytometry. Confocal microscopy showed the interactions of the two cell populations such as cell fusion and formation of intercellular nanotubes. Flow cytometry analysis revealed 3 clusters of damaged cells which can be plotted on a graph and analyzed statistically. These populations can be investigated separately and conclusions can be drawn on these data on the effectiveness of the simulated therapeutical approach.

Stem Cell Transplantation in an in vitro Simulated Ischemia/Reperfusion Model

We demonstrate how to set up an in vitro ischemia/reperfusion model and how to evaluate the effect of stem cell therapy on postischemic cardiac cells.

Stem cell transplantation protocols are finding their way into clinical practice1,2,3. Getting better results, making the protocols more robust, and ...

Using Quantitative Real-time PCR to Determine Donor Cell Engraftment in a Competitive Murine Bone Marrow Transplantation Model

Murine bone marrow transplantation models provide an important tool in measuring hematopoietic stem cell (HSC) functions and determining genes/molecules that regulate HSCs. In these transplant model systems, the function of HSCs is determined by the ability of these cells to engraft and reconstitute lethally irradiated recipient mice. Commonly, the donor cell contribution/engraftment is measured by antibodies to donor- specific cell surface proteins using flow cytometry. However, this method heavily depends on the specificity and the ability of the cell surface marker to differentiate donor-derived cells from recipient-originated cells, which may not be available for all mouse strains. Considering the various backgrounds of genetically modified mouse strains in the market, this cell surface/ flow cytometry-based method has significant limitations especially in mouse strains that lack well-defined surface markers to separate donor cells from congenic recipient cells. Here, we reported a PCR-based technique to determine donor cell engraftment/contribution in transplant recipient mice. We transplanted male donor bone marrow HSCs to lethally irradiated congenic female mice. Peripheral blood samples were collected at different time points post transplantation. Bone marrow samples were obtained at the end of the experiments. Genomic DNA was isolated and the Y chromosome specific gene, Zfy1, was amplified using quantitative Real time PCR. The engraftment of male donor-derived cells in the female recipient mice was calculated against standard curve with known percentage of male vs. female DNAs. Bcl2 was used as a reference gene to normalize the total DNA amount. Our data suggested that this approach reliably determines donor cell engraftment and provides a useful, yet simple method in measuring hematopoietic cell reconstitution in murine bone marrow transplantation models. Our method can be routinely performed in most laboratories because no costly equipment such as flow cytometry is required.

Determining donor cell engraftment presents a challenge in mouse bone marrow transplant models that lack well-defined phenotypical markers. We described a methodology to quantify male donor cell engraftment in female transplant recipient mice. This method can be used in all mouse strains for the study of HSC functions.

Murine bone marrow transplantation models provide an important tool in measuring hematopoietic stem cell (HSC) functions and determining genes/molecules ...

Murine Model of Wound Healing

Wound healing and repair are the most complex biological processes that occur in human life. After injury, multiple biological pathways become activated. Impaired wound healing, which occurs in diabetic patients for example, can lead to severe unfavorable outcomes such as amputation. There is, therefore, an increasing impetus to develop novel agents that promote wound repair. The testing of these has been limited to large animal models such as swine, which are often impractical. Mice represent the ideal preclinical model, as they are economical and amenable to genetic manipulation, which allows for mechanistic investigation. However, wound healing in a mouse is fundamentally different to that of humans as it primarily occurs via contraction. Our murine model overcomes this by incorporating a splint around the wound. By splinting the wound, the repair process is then dependent on epithelialization, cellular proliferation and angiogenesis, which closely mirror the biological processes of human wound healing. Whilst requiring consistency and care, this murine model does not involve complicated surgical techniques and allows for the robust testing of promising agents that may, for example, promote angiogenesis or inhibit inflammation. Furthermore, each mouse acts as its own control as two wounds are prepared, enabling the application of both the test compound and the vehicle control on the same animal. In conclusion, we demonstrate a practical, easy-to-learn, and robust model of wound healing, which is comparable to that of humans.

A murine model of cutaneous wound healing that can be used to assess therapeutic compounds in physiological and pathophysiological settings.

Wound healing and repair are the most complex biological processes that occur in human life. After injury, multiple biological pathways become activated. ...

Transplantation of Adipose Tissue-Derived Stem Cell Sheet to Reduce Leakage After Partial Colectomy in A Rat Model

Anastomotic leakage is a disastrous complication after colorectal surgery. Although current methods for leakage prevention have different levels of clinical efficacy, they are until now imperfect solutions. Stem cell therapy using ASC sheets could provide a solution to this problem. ASCs are considered as promising candidates for promoting tissue healing because of their trophic and immunomodulatory properties. Here, we provide methods to produce high-density ASC sheets, that are transplanted onto a colorectal anastomosis in a rat model to reduce the leakage. ASCs formed cell sheets in thermo-responsive culture dishes that could be easily detached. On the day of the transplantation, a partial colectomy with a 5-suture colorectal anastomosis was performed. Animals were immediately transplanted with 1 ASC sheet per rat. ASC sheets adhered spontaneously to the anastomosis without any glue, suture, or any biomaterial. Animal groups were sacrificed 3 and 7 days postoperatively. Compared to transplanted animals, the incidence of anastomotic abscesses and leakage was higher in control animals. In our model, the transplantation of ASC sheets after colorectal anastomosis was successful and associated with a lower leakage rate.

The preparation and transplantation of adipose tissue derived stem cell (ASC) sheets onto insufficiently sutured colorectal anastomoses in a rat model is presented. This novel application shows that ASC sheets can reduce colorectal anastomosis leakage.

Anastomotic leakage is a disastrous complication after colorectal surgery. Although current methods for leakage prevention have different levels of ...

Corneal Epithelial Abrasion with Ocular Burr As a Model for Cornea Wound Healing

The murine cornea provides an excellent model to study wound healing. The cornea is the outermost layer of the eye, and thus is the first defense to injury. In fact, the most common type of eye injury found in clinic is a corneal abrasion. Here, we utilize an ocular burr to induce an abrasion resulting in removal of the corneal epithelium in vivo on anesthetized mice. This method allows for targeted and reproducible epithelial disruption, leaving other areas intact. In addition, we describe the visualization of the abraded epithelium with fluorescein staining and provide concrete advice on how to visualize the abraded cornea. Then, we follow the timeline of wound healing 0, 18, and 72 h after abrasion, until the wound is re-epithelialized. The epithelial abrasion model of corneal injury is ideal for studies on epithelial cell proliferation, migration and re-epithelialization of the corneal layers. However, this method is not optimal to study stromal activation during wound healing, because the ocular burr does not penetrate to the stromal cell layers. This method is also suitable for clinical applications, for example, pre-clinical test of drug effectiveness.

This protocol describes a method to inflict an abrasion to the ocular surface of the mouse, and to follow the wound healing process thereafter. The protocol takes advantage of an ocular burr to partially remove the surface epithelium of the eye in anaesthetized mice.

The murine cornea provides an excellent model to study wound healing. The cornea is the outermost layer of the eye, and thus is the first defense to ...

Targeting Gray Rami Communicantes in Selective Chemical Lumbar Sympathectomy

Chemical lumbar sympathectomy (CLS) is a commonly used, minimally invasive procedure for the treatment of conditions including ischemic diseases of the lower extremities, hyperhidrosis, etc. It is commonly practiced to position the puncture needle tip in front of the anterior fascia of the psoas major muscle and inject the inactivating agent around the sympathetic trunk, which is defined as conventional CLS. Although relatively rare, ureteropelvic damage is the most frequently reported complication of conventional CLS and can cause serious harm to patients. We found that injecting the inactivating agent behind the anterior fascia, which only targets gray rami communicantes, helped achieve therapeutic efficacy in&#160;vasodilation, sweat reduction, and pain relief comparable to conventional CLS, and serious complications were largely reduced. We define this procedure as selective CLS. Here, we present a protocol of selective CLS. The precise needle tract and accurate evaluation of the spreading of the contrast agent are critical to ensure that the drug is injected behind the anterior fascia of the psoas major muscle. The needle tip is at approximately one-third the dividing line of the vertebral body in the lateral view of a lumbar X-ray. The contrast is mainly confined around the needle tip and spreads outward and downward along the psoas muscle fibers. In this way, the anterior fascia provides a natural barrier for the ureteropelvic area, and the psoas major muscle provides a natural barrier for the lumbar nerve root. There are several highlights of this article, including 1) a detailed description of the selective CLS procedures, 2) an explanation of the anatomical basis for the implementation of selective CLS, and 3) an explanation of the differences between selective and conventional CLS.

We present a protocol for selective chemical lumbar sympathectomy (CLS), which inactivates only gray rami communicantes and not the sympathetic trunk. Selective CLS can help achieve therapeutic efficacy in vasodilation, sweat reduction, and pain relief that are comparable to conventional CLS, and serious complications, particularly ureteropelvic damages, can be reduced.

Chemical lumbar sympathectomy (CLS) is a commonly used, minimally invasive procedure for the treatment of conditions including ischemic diseases of the ...

An Ex Vivo Tissue Culture Model for Fibrovascular Complications in Proliferative Diabetic Retinopathy

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes and one of the leading causes of blindness in working-age adults. No current animal models of diabetes and oxygen-induced retinopathy develop the full-range progressive changes manifested in human proliferative diabetic retinopathy (PDR). Therefore, understanding of the disease pathogenesis and pathophysiology has relied largely on the use of histological sections and vitreous samples in approaches that only provide steady-state information on the involved pathogenic factors. Increasing evidence indicates that dynamic cell-cell and cell-extracellular matrix (ECM) interactions in the context of three-dimensional (3D) microenvironments are essential for the mechanistic and functional studies towards the development of new treatment strategies. Therefore, we hypothesized that the pathological fibrovascular tissue surgically excised from eyes with PDR could be utilized to reliably unravel the cellular and molecular mechanisms of this devastating disease and to test the potential for novel clinical interventions. Towards this end, we developed a novel method for 3D ex vivo culture of surgically-excised patient-derived fibrovascular tissue (FT), which will serve as a relevant model of human PDR pathophysiology. The FTs are dissected into explants and embedded in fibrin matrix for ex vivo culture and 3D characterization. Whole-mount immunofluorescence of the native FTs and end-point cultures allows thorough investigation of tissue composition and multicellular processes, highlighting the importance of 3D tissue-level characterization for uncovering relevant features of PDR pathophysiology. This model will allow the simultaneous assessment of molecular mechanisms, cellular/tissue processes and treatment responses in the complex context of dynamic biochemical and physical interactions within the PDR tissue architecture and microenvironment. Since this model recapitulates PDR pathophysiology, it will also be amenable for testing or developing new treatments.

Here, we present a protocol to study the pathophysiology of proliferative diabetic retinopathy by using patient-derived, surgically-excised, fibrovascular tissues for three-dimensional native tissue characterization and ex vivo culture. This ex vivo culture model is also amenable for testing or developing new treatments.

Diabetic retinopathy (DR) is the most common microvascular complication of diabetes and one of the leading causes of blindness in working-age adults. No ...

An Enzyme-free Method for Isolation and Expansion of Human Adipose-derived Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are a population of multipotent cells that can be isolated from various adult and fetal tissues, including adipose tissue. As a clinically relevant cell type, optimal methods are needed to isolate and expand these cells in vitro. Most methods to isolate adipose-derived MSCs (ADSCs) rely on harsh enzymes, such as collagenase, to digest the adipose tissue. However, while effective at breaking down the adipose tissue and yielding a high ADSC recovery, these enzymes are expensive and can have detrimental effect on the ADSCs &#8212; including the risks of using xenogeneic components in clinical applications. This protocol details a method to isolate ADSCs from fresh lipoaspirate and abdominoplasty samples without enzymes. Briefly, this method relies on mechanical disassociation of any bulk tissue followed by an explant-type culture system. The ADSCs are permitted to migrate out of tissue and onto the tissue culture plate, after which the ADSCs can be cultured and expanded in vitro for any number of research and/or clinical applications.

This protocol provides an enzyme-free method for isolating mesenchymal stem cells from abdominoplasty and lipoaspirate samples using an explant method. The absence of harsh enzymes or centrifugation steps provides for clinically relevant stem cells that can be used for studies in vitro or transferred back to the clinic.

Mesenchymal stem cells (MSCs) are a population of multipotent cells that can be isolated from various adult and fetal tissues, including adipose tissue. ...